1. Field of the Invention
The present invention relates to a rotation controlling apparatus for controlling a rotation of a panel member, and an electronic apparatus which includes the rotation controlling apparatus and the panel member. More particularly, the present invention relates to a rotation controlling apparatus for controlling a rotation of the panel member, which is accommodated in a front panel (e.g., a dash board) within a compartment of a vehicle and is expanded or developed when it is used, when the panel member is accommodated or expanded, and an electronic apparatus which includes the rotation controlling apparatus and the panel member.
2. Description of the Related Art
Recently, an audio visual apparatus, such as a car audio, a navigation apparatus and so forth are installed in a compartment of an automobile or the like.
There are two methods to install a control panel for controlling the operations of the audio visual apparatus and the navigation apparatus or a display panel for displaying the operational state of those apparatuses in the compartment. That is, in one method, the control panel or the like is directly fixed to the dash board (which implies a portion containing an instrument panel in front of a driver seat, a glove box in front of an assistant seat and a panel portion between the instrument panel and the globe box, and hereafter, which is used in the same meaning) within the compartment. In the other method, when the control panel or the like is not used, it is accommodated in an accommodation room prepared within the dash board, and when it is used, its is pulled out from the accommodation room and is expanded to a usable position. In the latter method, an area or space required to use and accommodate the control panel or the like is narrower than that of the former method. Thus, the latter method is preferably used in such a case that the audio visual apparatus or the like is installed in a small vehicle in which a compartment itself is narrow.
For example, according to the latter method, a display panel as well as a shaft to rotate the display panel is accommodated in an accommodation room when the display panel is not used. In case of using the display panel, the display panel as well as the shaft is pulled and slid from the accommodation room. Then, after the display panel and the shaft are perfectly pulled out, the display panel is rotated with the shaft as a center, so that the display screen of the display panel can be located at a position opposite to a side of a passenger. On the other hand, in case of accommodating the display panel after the usage, the display panel is rotated to a position, at which the display panel can be drawn into the accommodation room (hereinafter, this position is referred to as an xe2x80x9caccommodation positionxe2x80x9d), with the shaft as a center and then, the display panel as well as the shaft is drawn and slid into the accommodation room.
The series of above-mentioned operations is done by driving a slide motor for sliding the display panel and the shaft and by driving a rotation motor for rotating the display panel with the shaft as the center. Here, in case of accommodating the display panel, it is necessary that the display panel is rotated to and stopped at the above mentioned accommodation position. In order to stop the display panel at this accommodation position, a mechanically pushing switch is employed, which is mechanically pushed to be actuated when the display panel is rotated to the accommodation position. In operation, when a part of the thrown down display panel pushes down the mechanically pushing switch, the rotation motor is controlled to be stopped in correspondence with the actuation of the mechanically pushing switch, and then the slide motor is controlled to be driven, so that the display panel is drawn and slid into the accommodation room.
However, the above-mentioned configuration certainly needs the mechanically pushing switch and some switching mechanism to operatively install the mechanically pushing switch. Thus, this results in a problem that the configuration is mechanically complex and its cost cannot be made lower.
Also, if the operation of accommodating and expanding the display panel is frequently repeated, there may be such a case that the mechanically pushing switch does not function well or the switching mechanism is failed or deformed because of an aged deterioration and the like. This results in a problem that it is difficult or impossible to detect that the position of the display panel becomes the accommodation position, and a problem that an erroneous position is recognized as the accommodation position. Moreover, those case lead to a problem that even if the display panel itself is physically stopped at a limit point of a rotatable range, the continuation of the rotation of the rotation motor causes the rotation motor to be broken, and also a problem that, even if at the time of the accommodation operation the display panel strikes or abuts an accommodation opening of the accommodation room and cannot be drawn, the continuation of the driving operation of the slide motor causes the slide motor to be broken.
The present invention is proposed in view of the above mentioned problems. It is therefore an object of the present invention to provide a rotation controlling apparatus, which can electrically detect a position around a shaft of a panel member (including a stop position at which the panel member should be stopped (e.g., the accommodation position), and hereafter, this position around the shaft of the display panel including the stop position is merely referred to as a xe2x80x9cposition of the display panelxe2x80x9d) such as a display panel or the like without using a mechanical configuration such as a mechanically pushing switch or the like, can surely stop the panel member at the stop position, and can surely accommodate the panel member into an accommodation room, and also an electronic apparatus having such a rotation controlling apparatus.
The above object of the present invention can be achieved by a rotation controlling apparatus for controlling a rotation of a panel member such as a display panel, which is rotated with a predetermined shaft as a center of the rotation. The rotation controlling apparatus is provided with: a signal generating device such as an encoder for generating a position detection signal indicative of an angular position of the panel member around the shaft in response to a rotation of the panel member around the shaft; and a controller such as a micro computer for controlling the rotation of the panel member in accordance with the position detection signal generated by the signal generating device, so as to stop the rotation of the panel member by using as a standard a generation timing of the position detection signal, which has a predetermined signal value based on a stop position signal value implying a value of the position detection signal indicative of a stop position at which the rotation of the panel member should be stopped.
According to the rotation controlling apparatus of the present invention, since the angular position of the panel member around the shaft can be electrically detected, it is possible to detect the angular position of the panel member without using a mechanical structure such as a mechanically pushing switch.
Therefore, it is possible to detect the angular position of the panel member around the shaft while preventing (i) the aged deterioration of the mechanical structure associated with the detection of the stop position and (ii) the structure of the apparatus from becoming complicated, and also reducing the cost.
In one aspect of the rotation controlling apparatus of the present invention, the controller uses as the standard the generation timing of the position detection signal corresponding to an added signal value, in which a generation error signal value implying a value of the position detection signal set in advance to compensate a generation error, which may be included in the position detection signal, is added on the stop position signal value.
According to this aspect, since the panel member is stopped while using as the standard the generation timing of the position detection signal corresponding to the added signal value, it is possible to compensate the generation error, which may be included in the position detection signal, and to thereby precisely stop the rotation of the panel member at the stop position.
Therefore, even if an error is generated in the relationship between the output value of the position detection signal and the actual angular position of the panel member around the shaft, it is possible to compensate this error, so that it is possible to precisely stop the rotation of the panel member at the stop position.
In this aspect, the controller may stop the rotation of the panel member, when a rotation time duration, which is set in advance as a time duration from the generation timing of the position detection signal corresponding to the added signal value until the panel member arrives in an allowable error range of the angular position which is set in advance in correspondence with the stop position, has elapsed from the generation timing of the position detection signal corresponding to the added signal value.
According to this aspect, even if any kind of the generation error is generated at the generation timing of the position detection signal, it is possible to stop the panel member within the allowable error range with the stop position as the standard.
In another aspect of the rotation controlling apparatus of the present invention (i) the signal generating device is provided with: an annular resistor which is rotated in conjunction with the rotation of the panel member and to both end terminals of which a voltage corresponding to a predetermined constant voltage value is applied; and a slide contact which contacts with the resistor while rotating, and (ii) the signal generating device outputs, as a value of the position detection signal, a voltage value of a voltage generated between the slide contact and one of the end terminals of the resistor in conjunction with the rotation of the panel member.
According to this aspect, it is possible to generate the position detection signal by means of a relatively simple construction.
In another aspect of the rotation controlling apparatus of the present invention, the stop position is the angular position at which the panel member can be accommodated into an accommodation room portion by a straight movement of the shaft after the panel member stops.
According to this aspect, since the panel member is surely stopped at the stop position after the rotation, it is possible to surely accommodate the panel member into the accommodation room portion after that.
In this aspect that the panel member can be accommodated into the accommodation room portion, when an accommodation of the panel member into the accommodation room portion is completed, the controller may update the stop position signal value to a value of the position detection signal, which is outputted at a timing when the accommodation is completed.
By constructing in this manner, since the stop position signal value is updated by assuming as the stop position the position of the panel member, which could actually allow the completion of the accommodation of the panel member, it is possible to smoothly complete the next operation of accommodating the panel member even if the error is included in the generation of the position detection signal.
In this aspect that the panel member can be accommodated into the accommodation room portion, when an accommodation of the panel member into the accommodation room portion is not possible, the controller may update the stop position signal value to an initial value, which is set in advance as a value of the position detection signal indicative of the stop position at which the panel member can be accommodated into the accommodation room portion.
By constructing in this manner, since the stop position signal value is updated to the initial value when the accommodation of the panel member could not be completed, it is possible to smoothly complete the next operation of accommodating the panel member.
In this aspect that the panel member can be accommodated into the accommodation room portion, the panel member may comprise one of a display panel for displaying information related to a vehicle navigation process to guide a vehicle and an operation panel for performing an operation to control an audio visual apparatus of vehicle installation type, and the stop position may comprise one of the angular position where the information is displayed by the display panel and the angular position where the operation is performed by the operation panel.
By constructing in this manner, as for the display panel, it is possible to surely complete the accommodation of the display panel into the accommodation room portion, and also possible to accurately expand the display panel at the display position when executing the display.
On the other hand, as for the operation panel, it is possible to surely complete the accommodation of the operation panel into the accommodation room portion, and also possible to accurately expand the operation panel at the operation execution position when executing the operation.
The above object of the present invention can be also achieved by an electric apparatus provided with (i) a panel member such as a display panel, which is rotated with a predetermined shaft as a center of the rotation, (ii) an accommodation room portion into which the panel member can be accommodated, (iii) a rotation controlling apparatus for controlling a rotation of the panel member provided with: a signal generating device such as an encoder for generating a position detection signal indicative of an angular position of the panel member around the shaft in response to a rotation of the panel member around the shaft; and a controller such as a micro computer for controlling the rotation of the panel member in accordance with the position detection signal generated by the signal generating device, so as to stop the rotation of the panel member by using as a standard a generation timing of the position detection signal, which has a predetermined signal value based on a stop position signal value implying a value of the position detection signal indicative of a stop position at which the rotation of the panel member should be stopped, the stop position being the angular position at which the panel member can be accommodated into the accommodation room portion by a straight movement of the shaft after the panel member stops, and (iv) an accommodating device such as a slider motor driver for accommodating the panel member and the rotation controlling apparatus in one body into the accommodation room portion, the accommodation room portion being installed in a dash board within a compartment of a vehicle.
According to the electric apparatus of the present invention, it is possible to surely accommodate the panel member into the accommodation room portion in the dash board within the compartment of the vehicle.
In one aspect of the electric apparatus of the present invention, the accommodating device accommodates the panel member and the rotation controlling apparatus in one body into the accommodation room portion, by straightly moving the shaft after the rotation of the panel member is stopped.
According to this aspect, it is possible to accommodate the panel member while preventing the panel member from striking or abutting an opening etc., of the accommodation room portion, in the middle of accommodating the display panel by straightly moving the shaft for rotating the panel member.
The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.